(solved) Urgent problem .

so i "had" a tqfp100 IDT7009 chip that is small with pins that are very close to they each other . i made a PCB as an adapter for the chip and it was all going great then it was time for soldering , a guy next door said he could do it so i sent the chip to him and the adapter PCB , what he did was a total catastrophie , almost every pin on the chip is connected to the one next to it . and the whole thing is messed up some pins are slightly bent but no pin was removed from the chip ...

can the situation be saved ?? ( i had to wait for almost 2 monthes for this chip to arrive and it did const almost 80$ , i am out of money and buying a new chip is almost impossible)

You could try sending to the guys at www.proto-advantage.com, they'll charge a small fee and rework it for you with proper tools.

CrossRoads:
You could try sending to the guys at www.proto-advantage.com, they'll charge a small fee and rework it for you with proper tools.

thank you very much CrossRoads . though i unfortunately cannot do that since i live in the middle of nowhere and sending something to an address in the United states is nearly impossible .

  • though could the chip be permanently damaged or dead ?
  • can the chip be unsoldered from the Adapter ?

thank you

Post some -clear- pictures of the bodge job - then maybe we can give you more help based on what the setup looks like. If you can get some clear (not blurry) close-up macro shots, that would be even better to diagnose with.

It may be a complete loss - or it may be something salvageable. Without pictures, it is impossible to tell.

Solder wick is great at cleaning up pins joined with solder.

a guy next door

I hope this guy is not your friend.

You could try ordering some Chipquik

http://www.chipquik.com/store/

Is this the adaptor board you're using?

I take it this is the same project as this earlier thread?

While I don't think a chip like the one you have would be easy to solder, it doesn't look too bad. I think some solder wick might solve your trouble.

pwillard:
I hope this guy is not your friend.

You could try ordering some Chipquik

Chip Quik -

+1 to Chipquik. It's a great way to remove valuable parts.

But only if you need to remove the chip. Without seeing a photo of the chip it's hard to know if it could be saved with solder wick or not.

Is the chip removed from the board?

Rework is usually more difficult than original assembly... I've managed to avoid surface mount at home...

A heat gun or hot-air soldering pencil may help. Where I used to work, we had a surface-mount rework station that used a hot-air bath pre-warmer, a hot-air pencil, and low-melt solder. But, for the fine-pitch parts like you have, we'd send the board to our board assembly house for rework. I could remove the parts, but I couldn't re-solder them without getting shorts.... And most of the time when we removed a part, we'd install a new-fresh part.

Some low-temperature solder may be helpful to you. When it melts, it blends with the existing solder making the whole mess easier to remove.

If wanted to re-use a part that had been removed, I would sometimes heat the leads with the hot-air pencil while holding the part with tweezers. Then, I'd slap the tweezers against the workbench to knock-off the hot solder. (The mix of regular and low-temperature solder makes this easier.)

Where I work now, we have a rework-expert with microscopes, fine soldering irons, some other tools, and lots of skill and experience. And of course, the original assembly is done with robotic machinery... The solder is precisely applied to the pads via a silkscreen process, and it's soldered in a special oven.

Thank you very much for the support guys
here are a couple of pictures of the current situation :

the same guy ( a friend ) offered to remove the chip using a heat gun ... i am in doubt since he seemed as sure the first time that the chip will be correctly soldered as sure he is now that nothing will happen to it

The chip looks like it's aligned correctly. IMO, some flux, solder and solder wick should be able to clean it up.

DuaneDegn:
The chip looks like it's aligned correctly. IMO, some flux, solder and solder wick should be able to clean it up.

it indeed is aligned correctly i admit . the issue is that the pins are nearly all shorted

Most of those pins look like they’re soldered correctly to me. How many of them are bridged? Can you see, looking at them, that they are bridged? (ie you did check that the board didn’t have bridged pins before you soldered it down, right? underetching can be a problem on hand-made boards).

Usually when I solder packages like that down, I end up with bridged pins, but those are usually easy to fix. I sometimes have to remove some solder, but with hand-made boards, you can just drag the iron along the trace, and some solder follows.

DrAzzy:
Most of those pins look like they're soldered correctly to me. How many of them are bridged? Can you see, looking at them, that they are bridged? (ie you did check that the board didn't have bridged pins before you soldered it down, right? underetching can be a problem on hand-made boards).

Usually when I solder packages like that down, I end up with bridged pins, but those are usually easy to fix. I sometimes have to remove some solder, but with hand-made boards, you can just drag the iron along the trace, and some solder follows.

yeah . i did test with a miltimeter , even though many pins are wired correctly , most of them are not .
what do you recommend ? removing the chip ? or working with that PCB ?

he chip looks like it’s aligned correctly. IMO, some flux, solder and solder wick should be able to clean it up.

I agree.

Flood it with flux and drag/reflow… should fix any issues

pwillard:
I agree.

Flood it with flux and drag/reflow... should fix any issues

the damage does not appear so clearly on the picture ... i highly doubt that flux and some solder could repair it . though can it be safely removed ??

Always with surface mount the trick is to use as little solder as possible. Just tinning the pads will
mean there is plenty of solder available - everything else is cleanliness and lots of flux - never handle
the chip pins because any finger grease will char and might prevent the pin being wetted by the solder.

I solder surface mount with a modified sandwich toaster using solder paste applied through a laser-cut
stencil - this is the simplest and most reliable approach, but you do need the equipment and to get
the stencil made. Occasionally I get a pair of pins shorted and fresh solder wick with flux is usually the
solution.

MarkT:
Always with surface mount the trick is to use as little solder as possible. Just tinning the pads will
mean there is plenty of solder available - everything else is cleanliness and lots of flux - never handle
the chip pins because any finger grease will char and might prevent the pin being wetted by the solder.

I solder surface mount with a modified sandwich toaster using solder paste applied through a laser-cut
stencil - this is the simplest and most reliable approach, but you do need the equipment and to get
the stencil made. Occasionally I get a pair of pins shorted and fresh solder wick with flux is usually the
solution.

thank you very much Mike , though professionals like you are nearly no where to be found in my area . i contacted a company that has professionals and good equipment though they only do large quantities .

though i hope the chip hasn't been damaged , tomorrow i will send the PCB for the chip to be removed with heat . thank you very much guys for the good knowledge . problem solved

amine2:
thank you very much Mike , though professionals like you are nearly no where to be found in my area . i contacted a company that has professionals and good equipment though they only do large quantities .

though i hope the chip hasn't been damaged , tomorrow i will send the PCB for the chip to be removed with heat . thank you very much guys for the good knowledge . problem solved

I dunno ... it looks to me like removing the chip could leave you with a chip with some of the tiny leads soldered together, and the board having excess solder on it. Then you'll have a much harder time getting it back on. I think I would try a solder wick before trying to remove the chip. Like this:

Put the wick on top of the joints, put some flux on the wick if necessary (it should come fluxed), and heat it from the top. It will take a while, but eventually the heat from the hot wick will melt the solder, and most of it will flow onto the wick. Once this happens drag the wick slowly, away from the center, from the chip, the excess solder will stay with the wick, and your joints will be much better. Clean them up with a sharp Xacto nib.

IMO, removing the chip without turning it into something for your "dead IC's" drawer will be very difficult.

Take a look at your other copies of that board, if any - check that the pads on the PCB aren't shorted. When I was making my own boards, I had a very hard time making such fine pitch pads come out without bridging;

DrAzzy:
IMO, removing the chip without turning it into something for your "dead IC's" drawer will be very difficult.

If the chip is still good, I think Chipquik (as suggested by pwillard) could be used to remove it without damage.